Volume 1

A treatise on hygiene and public health / edited by Thomas Stevenson and Shirley F. Murphy.

Date:
1892-1894
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on hygiene and public health / edited by Thomas Stevenson and Shirley F. Murphy. Source: Wellcome Collection.

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    the rapids can easily be inferred from the direction of motion at the orifice and the extent of the rapids. The energy of the motion of the issuing air is more dissipated in eddies SCALE % Fig. 24. if the velocity of entry be greater, as the diagrams indicate, thus a rapid current of air will cause more complete mixing with the air in the room than the slow delivery of tbe same quantity of air through a larger opening; but, SCALE r/a Fig. 25. on the other hand, the greater velocity means a much more definite current for a short distance, and hence may cause unendurable draughts, whereas the slow delivery may cause more widely extended draughts, which though unpleasant are not classed as unendurable. We have reproduced, also, three diagrams of inlets (figs. 24, 25, and 26),
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